Functionalized aerogel electromagnetic wave trap shielding system driven by synergistic absorption and reflection mechanism and preparation method thereof

Abstract

The invention discloses a functionalized aerogel electromagnetic wave trap shielding system driven by a synergistic absorption and reflection mechanism and a preparation method thereof, and the method comprises the following steps: 1, weighing lignocellulose nanofiber gel, adding deionized water, and carrying out high-speed shearing to obtain an LCNF aqueous phase solution; 2, taking a graphene oxide aqueous solution, the LCNF aqueous phase solution and the magnetic MOFs powder, mixing and stirring to obtain a GO / LCNF / MOF aqueous phase solution; 3, weighing POSS-NH2, and dissolving the POSS-NH2 in n-hexane, so as to obtain a POSS-NH2 oil phase solution; 4, the POSS-NH2 oil phase solution and the GO / LCNF / MOF water phase solution are mixed and stirred, and viscous gel with definite boundary is obtained; 5, transferring the viscous gel into a mold, freeze-drying, and annealing in an argon atmosphere to obtain aerogel; and 6, integrating the aerogel with the metal substrate to obtain a functionalized aerogel electromagnetic wave trap shielding system driven by a synergistic absorption and reflection mechanism, so that multiple scattering, reflection and multiple absorption of electromagnetic waves are realized, and the shielding efficiency and broadband response to electromagnetic interference are improved.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic interference shielding materials and device structures, specifically a functionalized aerogel electromagnetic wave trap shielding system driven by a synergistic absorption and reflection mechanism and its preparation method. Background Technology

[0002] With the rapid development of wireless communication, radar systems, and integrated circuits, electromagnetic interference (EMI) problems are becoming increasingly severe. Although traditional metal shielding materials have excellent reflection performance, they still have the following drawbacks: 1) They are too heavy, which limits lightweight design in portable, wearable, and aerospace fields; 2) In high-frequency or multi-source interference environments, the shielding effect gradually decreases, and they are prone to corrosion and difficult to process; 3) More importantly, they mainly rely on reflection mechanisms, which can easily generate secondary radiation or leakage of electromagnetic waves, which is not conducive to electromagnetic compatibility (EMC) design in complex environments.

[0003] Lightweight porous conductive materials (such as carbon-based aerogels) have been widely used in the development of novel absorbing EMI shielding materials due to their high specific surface area, three-dimensional network structure, and good electrical conductivity. Absorbing materials can convert electromagnetic energy into heat energy through dielectric loss, magnetic loss, and multiple scattering, thereby significantly suppressing interference echoes caused by reflection. In particular, under the synergistic effect of conductive networks and magnetic nanoparticles, multiple dissipation paths can be formed, effectively broadening the absorption bandwidth and improving shielding performance.

[0004] However, relying solely on the material's own absorption mechanism is insufficient to completely eliminate the energy of the transmitted wave, and secondary radiation leakage may still occur at the edge or inside of the device, reducing the overall EMI shielding effect. Therefore, how to construct a synergistic mechanism of "absorption + reflection" at the material structure level so that electromagnetic waves can still be effectively captured and repeatedly absorbed after penetration is a major technical bottleneck in the design of current high-efficiency electromagnetic shielding systems. Summary of the Invention

[0005] The purpose of this invention is to provide a functionalized aerogel electromagnetic wave trap shielding system driven by a synergistic absorption and reflection mechanism and its preparation method. By integrating functionalized aerogel materials and a metal substrate, multiple scattering, reflection and absorption of electromagnetic waves are achieved, which significantly improves the shielding efficiency and broadband response of electromagnetic waves.

[0006] This invention is achieved through the following technical solution:

[0007] A method for preparing a functionalized aerogel electromagnetic wave trap shielding system driven by a synergistic absorption and reflection mechanism includes the following steps:

[0008] Step 1: Weigh the lignocellulose nanofiber gel, add deionized water, and perform high-speed shearing to obtain an LCNF aqueous solution with a concentration of 8-10 mg / mL;

[0009] Step 2: Take 8-10 mg / mL of graphene oxide aqueous solution, LCNF aqueous solution and ZIP-8@Fe3O4 in a mass ratio of 1:1:(0.02-0.05), mix and stir to obtain GO / LCNF / MOF aqueous solution;

[0010] Step 3: Weigh out POSS-NH2 and dissolve it in n-hexane to obtain a POSS-NH2 oil phase solution with a concentration of 1-3 mg / mL;

[0011] Step 4: Mix the POSS-NH2 oil phase solution and the GO / LCNF / MOF aqueous phase solution at a mass ratio of 1:3, stir, and obtain a well-defined viscous gel.

[0012] Step 5: Transfer the viscous gel to a mold, freeze dry it, and then transfer it to a tube furnace. Anneal it at 800°C for 1 hour under an argon atmosphere to obtain an aerogel.

[0013] Step 6: Integrate the aerogel with the metal substrate to obtain a functionalized aerogel electromagnetic wave trap shielding system driven by synergistic absorption and reflection mechanisms.

[0014] Furthermore, the lignocellulose nanofiber gel from step 1 is prepared by the following method:

[0015] Step 1.1: First, adjust the moisture content of the chemithermomechanical slurry to 7wt%, then add 10g to 100g of maleic anhydride. React at 120℃ for 3h, then vacuum filter, and then wash with deionized water to remove excess maleic anhydride to obtain product A.

[0016] Step 1.2: Disperse product A in 500 mL of deionized water, add 30 mL of 1 M NaOH solution, and adjust the pH value to 11 to obtain slurry B;

[0017] Step 1.3: The pulp B is subjected to dialysis for 5 days to remove unreacted small molecules and byproducts, resulting in esterified modified cellulose pulp.

[0018] Step 1.4: Concentrate the esterified cellulose slurry to 2 wt%, and perform a single flow-through nanofiber disintegration treatment using a high-pressure microfluidic homogenizer with a nozzle orifice diameter of 0.13 mm and a working pressure of 30,000 psi to obtain lignocellulose nanofiber gel.

[0019] Further, the ZIP-8@Fe3O4 obtained in step 2 is prepared by the following method:

[0020] Step 2.1: Add Fe3O4 to the mixture of methanol and ethanol, stir for 10-12 minutes to obtain a suspension;

[0021] Step 2.2: Add 2-methylimidazole to the suspension according to the mass ratio of 2-methylimidazole to Fe3O4 7:(1-3), and sonicate for 20-22 min to obtain a mixed solution;

[0022] Step 2.3: According to the mass ratio of Zn(NO3)2·6H2O to 2-methylimidazole (0.8~1):1, add Zn(NO3)2·6H2O to a mixture of methanol and ethanol, stir for 10~12 min, let stand for 20~24 h, and then collect the precipitate with a strong magnet.

[0023] Step 2.4: First, wash the precipitate 2-3 times with anhydrous ethanol, then dry it under vacuum at 60-70℃ for 12 hours to obtain ZIP-8@Fe3O4.

[0024] Furthermore, the methanol and ethanol mixture in steps 2.1 and 2.3 is prepared by mixing anhydrous methanol and anhydrous ethanol in a volume ratio of 1:1.

[0025] Furthermore, the water content of the anhydrous ethanol in step 2.4 is less than 0.005%.

[0026] Furthermore, the stirring in step 2 is performed at a speed of 500 rpm using magnetic stirring for 1 to 2 hours.

[0027] Furthermore, the stirring time in step 4 is 30 to 35 minutes.

[0028] Furthermore, the freeze-drying in step 5 is carried out using a freeze dryer, first freezing at -85°C for 24 hours, and then freeze-drying at -60°C for 48 hours.

[0029] Furthermore, the metal substrate in step 6 is a titanium mesh.

[0030] A functionalized aerogel electromagnetic wave trap shielding system driven by a synergistic absorption and reflection mechanism.

[0031] The present invention has the following beneficial technical effects:

[0032] 1) This invention integrates an aerogel functional layer doped with magnetic MOF nanoparticles with a conductive metal substrate to construct a three-dimensional shielding structure with interface impedance matching, internal multi-scale dissipation, and enhanced bottom reflection. When electromagnetic waves impact the surface of the cryogel, the material's inherent limited conductivity combined with the synergistic enhancement effect of the magnetic MOFs achieves impedance matching and minimizes surface reflection. When electromagnetic waves penetrate the aerogel functional layer, the penetrating electromagnetic waves undergo multiple internal scatterings within the multi-scale porous structure of the aerogel layer, dissipating energy through ohmic loss, dielectric loss, and magnetic loss mechanisms. When the residual electromagnetic waves reach the conductive metal substrate, they are reflected back to the aerogel layer and then absorbed again, thus achieving efficient attenuation of electromagnetic waves. In short, this invention introduces a synergistic path of "magnetic loss enhanced absorption + metal reflection re-absorption" into the aerogel electromagnetic shielding structure, achieving synergistic control of multiple dissipation mechanisms and shielding paths. This significantly improves the shielding efficiency, absorption capacity, and broadband response of electromagnetic waves, solving the problem of secondary radiation or leakage of electromagnetic waves. It provides a new path for high-performance, integrable, and lightweight EMI shielding systems and has broad application prospects.

[0033] 2) The functionalized aerogel electromagnetic wave trap shielding system proposed in this invention not only exhibits excellent shielding performance and low reflection characteristics, but also has good mechanical flexibility and environmental adaptability. It is especially suitable for lightweight design in emerging fields such as flexible electronic devices, 5G communication protection, precision instruments and anti-interference of aerospace equipment. It provides a new design concept for the development of absorption-reflection synergistic shielding materials and expands the path for the engineering application of high-performance aerogels in the field of electromagnetic shielding.

[0034] 3) This invention not only has a simple and controllable preparation process, making it suitable for large-scale production, but also is applicable to the efficient shielding construction of flexible electronic devices, electromagnetic compatibility systems, and safety protection materials in complex environments, and has broad engineering application prospects. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of the functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism prepared in this invention;

[0036] Figure 2 This represents the total shielding effectiveness of the functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism prepared in Examples 1 and 2 of this invention.

[0037] Figure 3 The absorption and reflection shielding effectiveness of the functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism prepared in Examples 1 and 2 of this invention is demonstrated.

[0038] Figure 4It is the shielding coefficient of the functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism prepared in Examples 1 and 2 of this invention. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0040] The lignocellulose nanofiber gels selected in Real-Time Examples 1 to 4 of this invention were prepared by the following method:

[0041] Step 1: First, adjust the moisture content of the chemithermomechanical slurry to 7wt%, then add 10g to 100g of maleic anhydride. React at 120℃ for 3h, then vacuum filter, and then wash with deionized water to remove excess maleic anhydride to obtain product A.

[0042] Step 2: Disperse product A in 500 mL of deionized water, add 30 mL of 1 M NaOH solution, and adjust the pH value to 11 to obtain slurry B;

[0043] Step 3: The pulp B is subjected to dialysis for 5 days to remove unreacted small molecules and byproducts, resulting in esterified modified cellulose pulp.

[0044] Step 4: Concentrate the esterified cellulose slurry to 2 wt%, and perform a single flow-through nanofiber disintegration treatment using a high-pressure microfluidic homogenizer with a nozzle orifice diameter of 0.13 mm and a working pressure of 30,000 psi to obtain lignocellulose nanofiber gel.

[0045] Example 1

[0046] Step 1: Mix 80 mL of anhydrous methanol and 80 mL of anhydrous ethanol to obtain a methanol and ethanol mixture. Add 1.6 g of Fe3O4 to the methanol and ethanol mixture and stir for 10 min to obtain a suspension.

[0047] Step 2: Add 2-methylimidazole to the suspension according to the mass ratio of 2-methylimidazole to Fe3O4 of 7:1.5, and sonicate for 20 minutes to obtain a mixed solution;

[0048] Step 3: First, mix 80 mL of anhydrous methanol and 80 mL of anhydrous ethanol to obtain a mixture of methanol and ethanol. Then, according to the mass ratio of Zn(NO3)2·6H2O to 2-methylimidazole of 0.9:1, add Zn(NO3)2·6H2O to the mixture of methanol and ethanol, stir magnetically for 10 min, let stand at room temperature for 20 h, and then collect the precipitate with a strong magnet.

[0049] Step 4: First, wash the precipitate twice with anhydrous ethanol with a water content of less than 0.005%, and then dry it under vacuum at 70°C for 12 hours to obtain ZIP-8@Fe3O4.

[0050] Step 5: Weigh the lignocellulose nanofiber gel, add deionized water, and perform high-speed shearing to obtain an LCNF aqueous solution with a concentration of 8 mg / mL;

[0051] Step 6: Take 8 mg / mL of graphene oxide aqueous solution, LCNF aqueous solution and ZIP-8@Fe3O4 in a mass ratio of 1:1:0.02, mix them, and stir magnetically at 500 rpm for 2 h to obtain GO / LCNF / MOF aqueous solution.

[0052] Step 7: Weigh out POSS-NH2 and dissolve it in n-hexane to obtain a POSS-NH2 oil phase solution with a concentration of 1 mg / mL;

[0053] Step 8: Mix the POSS-NH2 oil phase solution and the GO / LCNF / MOF aqueous phase solution at a mass ratio of 1:3 and stir for 30 min to obtain a well-defined viscous gel.

[0054] Step 9: Transfer the viscous gel to a mold and place it in a freeze dryer. First, freeze it at -85°C for 24 hours, then freeze-dry it at -60°C for 48 hours. Then transfer it to a tube furnace and anneal it at 800°C for 1 hour under an argon atmosphere to obtain the aerogel.

[0055] Step 10: Lay the aerogel on the surface of the titanium mesh to obtain a functionalized aerogel electromagnetic wave trap shielding system driven by synergistic absorption and reflection mechanisms.

[0056] Example 2

[0057] Step 1: Mix 80 mL of anhydrous methanol and 80 mL of anhydrous ethanol to obtain a methanol and ethanol mixture. Add 1.6 g of Fe3O4 to the methanol and ethanol mixture and stir for 10 min to obtain a suspension.

[0058] Step 2: Add 2-methylimidazole to the suspension according to the mass ratio of 2-methylimidazole to Fe3O4 of 7:2, and sonicate for 20 minutes to obtain a mixed solution;

[0059] Step 3: First, mix 80 mL of anhydrous methanol and 80 mL of anhydrous ethanol to obtain a mixture of methanol and ethanol. Then, according to the mass ratio of Zn(NO3)2·6H2O to 2-methylimidazole of 1:1, add Zn(NO3)2·6H2O to the mixture of methanol and ethanol, stir magnetically for 10 min, let stand at room temperature for 22 h, and then collect the precipitate with a strong magnet.

[0060] Step 4: First, wash the precipitate twice with anhydrous ethanol with a water content of less than 0.005%, and then dry it under vacuum at 70°C for 12 hours to obtain ZIP-8@Fe3O4.

[0061] Step 5: Weigh the lignocellulose nanofiber gel, add deionized water, and perform high-speed shearing to obtain an LCNF aqueous solution with a concentration of 9 mg / mL;

[0062] Step 6: Take 9 mg / mL of graphene oxide aqueous solution, LCNF aqueous solution and ZIP-8@Fe3O4 in a mass ratio of 1:1:0.04, mix them, and stir magnetically at 500 rpm for 1 h to obtain GO / LCNF / MOF aqueous solution.

[0063] Step 7: Weigh out POSS-NH2 and dissolve it in n-hexane to obtain a POSS-NH2 oil phase solution with a concentration of 2 mg / mL;

[0064] Step 8: Mix the POSS-NH2 oil phase solution and the GO / LCNF / MOF aqueous phase solution at a mass ratio of 1:3 and stir for 30 min to obtain a well-defined viscous gel.

[0065] Step 9: Transfer the viscous gel to a mold and place it in a freeze dryer. First, freeze it at -85°C for 24 hours, then freeze-dry it at -60°C for 48 hours. Then transfer it to a tube furnace and anneal it at 800°C for 1 hour under an argon atmosphere to obtain the aerogel.

[0066] Step 10: Lay the aerogel on the surface of the titanium mesh to obtain a functionalized aerogel electromagnetic wave trap shielding system driven by synergistic absorption and reflection mechanisms.

[0067] Example 3

[0068] Step 1: Mix 80 mL of anhydrous methanol and 80 mL of anhydrous ethanol to obtain a methanol and ethanol mixture. Add 3.2 g of Fe3O4 to the methanol and ethanol mixture and stir for 12 min to obtain a suspension.

[0069] Step 2: Add 2-methylimidazole to the suspension at a mass ratio of 7:1 to Fe3O4, and sonicate for 22 min to obtain a mixed solution.

[0070] Step 3: First, mix 80 mL of anhydrous methanol and 80 mL of anhydrous ethanol to obtain a mixture of methanol and ethanol. Then, according to the mass ratio of Zn(NO3)2·6H2O to 2-methylimidazole of 1:1, add Zn(NO3)2·6H2O to the mixture of methanol and ethanol, stir magnetically for 11 min, let stand at room temperature for 22 h, and then collect the precipitate with a strong magnet.

[0071] Step 4: First, wash the precipitate three times with anhydrous ethanol with a water content of less than 0.005%, and then dry it under vacuum at 60°C for 12 hours to obtain ZIP-8@Fe3O4.

[0072] Step 5: Weigh the lignocellulose nanofiber gel, add deionized water, and perform high-speed shearing to obtain an LCNF aqueous solution with a concentration of 10 mg / mL;

[0073] Step 6: Take 10 mg / mL of graphene oxide aqueous solution, LCNF aqueous solution and ZIP-8@Fe3O4 in a mass ratio of 1:1:0.05, mix them, and stir magnetically at 500 rpm for 1.5 h to obtain GO / LCNF / MOF aqueous solution.

[0074] Step 7: Weigh out POSS-NH2 and dissolve it in n-hexane to obtain a POSS-NH2 oil phase solution with a concentration of 2 mg / mL;

[0075] Step 8: Mix the POSS-NH2 oil phase solution and the GO / LCNF / MOF aqueous phase solution at a mass ratio of 1:3, stir for 32 min, and obtain a well-defined viscous gel.

[0076] Step 9: Transfer the viscous gel to a mold and place it in a freeze dryer. First, freeze it at -85°C for 24 hours, then freeze-dry it at -60°C for 48 hours. Then transfer it to a tube furnace and anneal it at 800°C for 1 hour under an argon atmosphere to obtain the aerogel.

[0077] Step 10: Lay the aerogel on the surface of the titanium mesh to obtain a functionalized aerogel electromagnetic wave trap shielding system driven by synergistic absorption and reflection mechanisms.

[0078] Example 4

[0079] Step 1: Mix 80 mL of anhydrous methanol and 80 mL of anhydrous ethanol to obtain a methanol and ethanol mixture. Add 1.6 g of Fe3O4 to the methanol and ethanol mixture and stir for 11 min to obtain a suspension.

[0080] Step 2: Add 2-methylimidazole to the suspension according to the mass ratio of 2-methylimidazole to Fe3O4 of 7:3, and sonicate for 21 min to obtain a mixed solution;

[0081] Step 3: First, mix 80 mL of anhydrous methanol and 80 mL of anhydrous ethanol to obtain a mixture of methanol and ethanol. Then, according to the mass ratio of Zn(NO3)2·6H2O to 2-methylimidazole of 0.8:1, add Zn(NO3)2·6H2O to the mixture of methanol and ethanol, stir magnetically for 12 min, let stand at room temperature for 24 h, and then collect the precipitate with a strong magnet.

[0082] Step 4: First, wash the precipitate three times with anhydrous ethanol with a water content of less than 0.005%, and then dry it under vacuum at 65°C for 12 hours to obtain ZIP-8@Fe3O4.

[0083] Step 5: Weigh the lignocellulose nanofiber gel, add deionized water, and perform high-speed shearing to obtain an LCNF aqueous solution with a concentration of 10 mg / mL;

[0084] Step 6: Take 10 mg / mL of graphene oxide aqueous solution, LCNF aqueous solution and ZIP-8@Fe3O4 in a mass ratio of 1:1:0.03, mix them, and stir magnetically at 500 rpm for 1 h to obtain GO / LCNF / MOF aqueous solution.

[0085] Step 7: Weigh out POSS-NH2 and dissolve it in n-hexane to obtain a POSS-NH2 oil phase solution with a concentration of 3 mg / mL;

[0086] Step 8: Mix the POSS-NH2 oil phase solution and the GO / LCNF / MOF aqueous phase solution at a mass ratio of 1:3 and stir for 35 minutes to obtain a well-defined viscous gel.

[0087] Step 9: Transfer the viscous gel to a mold and place it in a freeze dryer. First, freeze it at -85°C for 24 hours, then freeze-dry it at -60°C for 48 hours. Then transfer it to a tube furnace and anneal it at 800°C for 1 hour under an argon atmosphere to obtain the aerogel.

[0088] Step 10: Lay the aerogel on the surface of the titanium mesh to obtain a functionalized aerogel electromagnetic wave trap shielding system driven by synergistic absorption and reflection mechanisms.

[0089] Figure 1 The diagram shows the structure of the functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism prepared in Examples 1 to 5. It can be seen that when electromagnetic waves penetrate the aerogel, the penetrating electromagnetic waves undergo multiple internal scatterings within the multi-scale porous structure of the aerogel, and dissipate energy through ohmic loss, dielectric loss and magnetic loss mechanisms. When the residual electromagnetic waves reach the conductive metal substrate, they are reflected back to the aerogel and then absorbed again, thereby achieving efficient attenuation of electromagnetic waves.

[0090] Figure 2 The total shielding effectiveness of the functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism prepared in Examples 1 and 2 against electromagnetic interference shows that the total shielding effectiveness against electromagnetic waves in the frequency range of 8.2 to 12.4 GHz is close to 50 dB, indicating that it has good broadband response and electromagnetic wave shielding efficiency.

[0091] Figure 3 The shielding efficiency of the functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism prepared in Examples 1 and 2 is shown. It can be seen that the aerogel synthesized in Examples 1 and 2 has a high absorption efficiency for electromagnetic waves. In addition, the metal substrate has a good reflection efficiency for electromagnetic waves, which makes the functionalized aerogel electromagnetic wave trap shielding system exhibit good electromagnetic wave shielding efficiency.

[0092] Figure 4 The shielding coefficients of the functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism prepared in Examples 1 and 2 are shown. It can be seen that the aerogel synthesized in Examples 1 and 2 has a high absorption coefficient for electromagnetic waves. In addition, the metal substrate has a high reflection coefficient for electromagnetic waves, so the functionalized aerogel electromagnetic wave trap shielding system exhibits a very high overall electromagnetic wave shielding efficiency.

Claims

1. A method for preparing a functionalized aerogel electromagnetic wave trap shielding system driven by a synergistic absorption and reflection mechanism, characterized in that, Includes the following steps: Step 1: Weigh the lignocellulose nanofiber gel, add deionized water, and perform high-speed shearing to obtain an LCNF aqueous solution with a concentration of 8-10 mg / mL; Step 2: Take 8-10 mg / mL of graphene oxide aqueous solution, LCNF aqueous solution and ZIP-8@Fe3O4 in a mass ratio of 1:1:(0.02-0.05), mix and stir to obtain GO / LCNF / MOF aqueous solution; Step 3: Weigh out POSS-NH2 and dissolve it in n-hexane to obtain a POSS-NH2 oil phase solution with a concentration of 1-3 mg / mL; Step 4: Mix the POSS-NH2 oil phase solution and the GO / LCNF / MOF aqueous phase solution at a mass ratio of 1:3, stir, and obtain a well-defined viscous gel. Step 5: Transfer the viscous gel to a mold, freeze-dry it, and then transfer it to a tube furnace. Anneal it at 800°C for 1 hour under an argon atmosphere to obtain an aerogel. Step 6: Integrate the aerogel with the metal substrate to obtain a functionalized aerogel electromagnetic wave trap shielding system driven by synergistic absorption and reflection mechanisms.

2. The method for preparing the functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism according to claim 1, characterized in that, The lignocellulose nanofiber gel in step 1 was prepared by the following method: Step 1.1: First, adjust the moisture content of the chemithermomechanical slurry to 7wt%, then add 10g to 100g of maleic anhydride. React at 120℃ for 3h, then vacuum filter, and then wash with deionized water to remove excess maleic anhydride to obtain product A. Step 1.2: Disperse product A in 500 mL of deionized water, add 30 mL of 1 M NaOH solution, and adjust the pH value to 11 to obtain slurry B; Step 1.3: The pulp B is subjected to dialysis for 5 days to remove unreacted small molecules and byproducts, resulting in esterified modified cellulose pulp. Step 1.4: Concentrate the esterified cellulose slurry to 2 wt%, and perform a single flow-through nanofiber disintegration treatment using a high-pressure microfluidic homogenizer with a nozzle orifice diameter of 0.13 mm and a working pressure of 30,000 psi to obtain lignocellulose nanofiber gel.

3. The method for preparing the functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism according to claim 1, characterized in that, The ZIP-8@Fe3O4 in step 2 is prepared by the following method: Step 2.1: Add Fe3O4 to the mixture of methanol and ethanol, stir for 10-12 minutes to obtain a suspension; Step 2.2: Add 2-methylimidazole to the suspension according to the mass ratio of 2-methylimidazole to Fe3O4 7:(1-3), and sonicate for 20-22 min to obtain a mixed solution; Step 2.3: According to the mass ratio of Zn(NO3)2·6H2O to 2-methylimidazole (0.8~1):1, add Zn(NO3)2·6H2O to a mixture of methanol and ethanol, stir for 10~12 min, let stand for 20~24 h, and then collect the precipitate with a strong magnet. Step 2.4: First, wash the precipitate 2-3 times with anhydrous ethanol, then dry it under vacuum at 60-70℃ for 12 hours to obtain ZIP-8@Fe3O4.

4. The method for preparing the functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism according to claim 3, characterized in that, The methanol and ethanol mixture in steps 2.1 and 2.3 is prepared by mixing anhydrous methanol and anhydrous ethanol in a volume ratio of 1:

1.

5. The method for preparing the functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism according to claim 3, characterized in that, The anhydrous ethanol in step 2.4 has a water content of less than 0.005%.

6. The method for preparing a functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism according to claim 1, characterized in that, The stirring in step 2 is performed at a speed of 500 rpm using magnetic stirring for 1 to 2 hours.

7. The method for preparing a functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism according to claim 1, characterized in that, The stirring time in step 4 is 30 to 35 minutes.

8. The method for preparing a functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism according to claim 1, characterized in that, The freeze-drying in step 5 is carried out using a freeze dryer, first freezing at -85°C for 24 hours, and then freeze-drying at -60°C for 48 hours.

9. The method for preparing a functionalized aerogel electromagnetic wave trap shielding system driven by the synergistic absorption and reflection mechanism according to claim 1, characterized in that, The metal substrate in step 6 is a titanium mesh.

10. A functionalized aerogel electromagnetic wave trap shielding system driven by a synergistic absorption and reflection mechanism, prepared by the method according to any one of claims 1 to 9.

Images